1. Field of the Invention
The present invention relates to a light emitting device (LED) assembly and a headlamp including the LED assembly, and more particularly, to an LED assembly and a headlamp including the LED assembly that may obtain high contrast while reducing a loss of light emitted from an LED.
2. Description of the Related Art
In general, a vehicle may incorporate a lamp system such as a headlamp and a tail lamp to recognize an object in a traveling direction while travelling at night and to inform other vehicles or other load users about a travel state of the vehicle. The headlamp may be referred to as a headlight, and indicate a lighting lamp that lights a path along which the vehicle travels. A daytime running light (DRL) may indicate a lamp enhancing perception of a vehicle during daytime hours to reduce a risk of accidents occurring.
An existing lamp for a vehicle may generally have a headlamp manufactured using a light source such as a halogen lamp, a high intensity discharge (HID), and the like. Here, an emitting pattern of the headlight is regulated, and an optical design or a physical shield cutoff of the headlight is used to conform to the regulation.
A light emitting device (LED) may correspond to a semiconductor device that generates light by an applied current. The LED may be superior to other light sources in terms of low power consumption, semi-permanent lifespan, fast response time, high light conversion efficiency, stability, environmental friendliness, and the like. Thus, a headlamp using an LED as a light source of a lamp for a vehicle has been developed recently. However, an LED headlamp used for a vehicle is in a first stage of development, and is being developed slowly.
A light collection structure of a conventional LED headlamp may include an LED light source, a reflector to control a direction of light generated by the LED headlamp, a lens to protect the LED light source, and a physical shield capable of blocking light emitted toward a vehicle from an opposite direction and to prevent a glare from the opposite direction affecting the vehicle.
As described in the foregoing, a light intensity may decrease when a cutoff shield is used to conform to regulations for an emitting pattern of a vehicle headlamp. Thus, an LED headlamp excluding the cutoff shield is being developed at an increased rate.
In a structure excluding the cutoff shield, a light emitted from a light source may disperse and as such, it may be difficult to obtain a desired contrast. In particular, to obtain a high contrast, light generated from an LED chip and being dispersed to a side of the LED chip may be blocked. Here, light extraction efficiency may be an essential element in the LED light source. Thus, contrast of an LED light source and the light extraction efficiency may be in a trade-off relationship.
Accordingly, there is a desired for a structure for enhancing contrast of an LED light source while preventing a decrease in light extraction efficiency.